@misc{cryptoeprint:2013:016,
author = {Jae Hong Seo and Keita Emura},
title = {Revocable Identity-Based Encryption Revisited: Security Model and Construction},
howpublished = {Cryptology ePrint Archive, Report 2013/016},
year = {2013},
note = {\url{http://eprint.iacr.org/}},
}
You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.